Getsimple htb accadmy

Hello there, I hope you’re all well

i have and issue with the module “Getting Started” specifically with this “Knowlage check”

which i could pass this login page i found a user
and i hashed the password
but after i loged in there’s a problem with upload files button in the page so why can i solve this?

otherwise i did and i suppmeted the flag using a metasploit module . but i’m still wondring how to do it manually