Strange `CaseClauseError`

Ah yes, that is correct now, you changed from Joken.generate_and_sign which you had in the previous post to Joken.generate_and_sign!. Joken.generate_and_sign returns a tuple, Joken.generate_and_sign! returns a string. However if you changed that it shoul dhave solved yout :erlang.apply error, so what’s the new error you have?