Can't deploy on Heroku

[stepersy]

Hi, I tried to deploy the apps through Heroku, but it didn't work. Heroku says:
"Create app
App creation failed. Please ensure you have valid values in the above form fields."

And

Error scaling dynos: Process tier is invalid. Available process tiers are Eco, Basic, Production, Private, and Shield.

What's the problem? I have an Heroku Student Plan (13$ at month)