Entrapta was first seen in season 1 episode 6, system failure, where Adora, Glimmer and Bow trek to Dryl to recruit Entrapta for Glimmer's new princess alliance. but when they get there they realise that a piece of first ones tech that entrapta was studying suddenly corrupted all the robots in dryl and everyone works together to save dryl and free the robots of the corruption.

The next most important event in her story is the rescue of Princess Glimmer and Bo after they got kidnapped by the horde after the mission at the princess ball to recruit princess Frosta for the princess alliance. As the princess alliance is making it's way through the FrightZone, Entrapta gets too distracted by the technology bulding up The Horde's home and seperates from Perfuma who she was meant to stay with. A bit of time later she reunites with Seahawk riding on her reprogrammed Horde Bots named E.M.I.L.Y and then the rest of the Princess Alliance and frees Bo and Glimmer. But when there about escape E.M.I.L.Y gets caught on a wire and entrapta tried to untangle it but the door closed and fire noises can be heard and...

jk
she actually lived and was living in the air vents of the Fright Zone. Until Catra found her after she was moving from air vent, Catra lied to her saying they left her behind and getting her to work on projects in the Fright Zone. here experiment was repowering the black garnet (scorpia's runestone) and transmitting the energy from it to power the all of the Fright Zone and putting all of etheria's nature going into completeby the powered up black garnet putting everything into an inbalanced state.
while living in the Fright Zone, Entrapta has found uncomplacent in here living conditions and her work effort has not been rewarded for making the newest models of horde bots. So she enters hordak's lab without knowing he was there, so when she stumbled upon him slouching under his work table out of this armor and his body is strangely deformed, trying to sneak away but instead tripped a wire and made many things fall until something big enough to catch Hordak's attention. And then that's when its revealed that Hordak is a failed clone of a galatic overlord.
HordePrime the true leader of the Horde, Hordak was a meant to be an ally of HordePrime, a Brother of his. but when being created there was a defect. And since HordePrime is hesitent on anything that isn't perfection,he sees them as something that shoudn't be in his image, in his brothership.so, he banished him sent to an alternate reality and Hordak formed the Horde in Etheria to regain his trust, to finally be seen as his brother. While in Etheria, he's been trying to create a new body to be acceptable to HordePrime.
feeling heart broken for Hordak she helps him create a new set of armour powered by a piece of first ones tech super charging it and giving hordak some insperational words.

the next important plot point in her story is when Catra returns to the Fright Zone after being ordered to go to the Crimson Waste, returning with She Ra's sword explaining that they'll be able to create a portal across dimensions to bring HordePrime's army to Etheria.
but when Catra said that they had to start the portal without testing further, Entrapta tried to block her from telling Hordak to wait longer before doing this, Catra in retaliation tazed her putting her on the transfer leaving for beast island that was meant to take Shadow-Weaver. and thats last time we see her except in the weird portal dimension so again...

I TRICKED YOU AGAIN!!!
So when Scorpia realises that she and E.M.I.L.Y aren't as happy without Entrapt there so she decides to leave the Frigth Zone with E.M.I.L.Y to head for Bright Moon to tell the princesses that Entrapta is on the transport to beast island. So Adora and Bow without permission from Glimmer go to rescue Entrapta on Mara's, the previous She-ra's ship. after they get lost meeting the previous king of bright moon, King Micah. after that they finally reunite with Entrapta and her big mech that sadly never got a name :(
she takes them to a monument filled with old archives of the FirstOnes and infodumps about the heart of Etheria explaining how Adora has no choice but to comply with the super weapon in the heart of Etheria blowing up the planet. as they were escaping entrapta stayed behind saying she never knew how to talk to people and be friends, only after getting a ted talk from Bow and mention of FirstOnes space ship and so she goes back to Brightmoon with them.
after finding out Glimmer and Scorpia have moved to the frightZone, Entrapta and Bow on SwiftWind as fast they could venture to the FrightZone but SwiftWind falls as She-ra starts taking all of the energy in Etheria and suddenly the planet is transported to an alternate universe, Despondo. into it's original universe and Lord Prime has started his conquest on Etheria.