In which mythical river was Achilles dipped, as an infant, yielding his vulnerable heel?

The story continues with Achilles being an invincible warrior , during the fighting of the Trojan War he was killed by an arrow shot by Paris . It maybe that Apollo guided the arrow into Achilles heel , his one vulnerable spot . This story is the source of the term ‘Achilles heel’ meaning a weak spot

so that's the whole story.. I like the new Netflix series

Achilles was not a god . I read another version where Demeter the goddess while searching for her daughter Persephone disguised herself as a mortal woman and was taking care of Achilles and actually was kind of roasting him in a fire to make him immortal but got caught by the mother who made Demeter stop before she got to his heel

Is He Achilles the god of war with one weakness(his heels not dipped in the river styx)