The idea of Let’s Encrypt is that web hosts should provide integrations for it, which automatically handle the issuing and renewal of your certificates. That generally requires intervention and cooperation from your web host.
There is a manual option, and that’s to manually issue your certificate (for example, using https://zerossl.com/free-ssl/#crt) and import it into your cPanel SS/TLS Manager. This works by ZeroSSL authorizing your domain and then giving you you a private key and Let’s Encrypt certificate to download, which you import into the SSL/TLS Manager in cPanel.
The manual option is strongly discouraged because it only provides the protection of a certificate for 90 days. It is not automatically renewed, you have to fully repeat the process at least every 90 days.
So you can understand that sticking to the AutoSSL option is preferable in the majority of cases, if you value not having the burden of manual renewal on your hands.
Your domain has been protected by AutoSSL since 2017. Are you saying that your host has been charging you for the use of AutoSSL?
You always have the option of moving to another cPanel host that does not charge for free and automatic SSL. There are plenty of them.
Nobody on this forum can do anything if your host is choosing to force people to pay for automated certificates.