Made in Abyss: Journey's Dawn (2019) on Netflix

Plot summary

Riko is a girl who has trained hard to become a Cave Raider, and she wants to follow in her mother's footsteps. The Abyss is a deadly and unforgiving chasm, yet explorers are drawn to it. Then Riko receives news that her mother died down inside it, along with a mysterious note that says the woman may still be alive. Riko sets out to learn what happened to her mother, and she journeys into the chasm with Reg, a humanoid robot boy. The two of them must find out whether they can survive a descent where so many others have perished.