Cant auth on PPP connection

I have problem with established ppp connection when SIM needs authentication (username and pw to APN). I removed line noauth and added text lines: user “YOUR USERNAME” and password “YOURPASSWORD”, but for every time if i do ‘sudo pon’ i have response:

/usr/bin/pppd: The remote system (3gppp) is required to authenticate itself
/usr/bin/pppd: but I couldn’t find any suitable secret (password) for it to user
to do so

Please help me.
Best regards

Hi @byczek2102,

About your issue, it is better to share more information with us. Can you post the contents of your provider file(/etc/ppp/peers/provider) and chap-secrets in /etc/ppp/?