PHP 8 compatibility

I use Simple OAuth on server with php version 8.0.2 and have following error:

Lcobucci\JWT\Signer\InvalidKeyProvided: It was not possible to parse your key, reason: in Lcobucci\JWT\Signer\InvalidKeyProvided::cannotBeParsed() (line 17 of /home/SITE/vendor/lcobucci/jwt/src/Signer/InvalidKeyProvided.php).

and couple deprecated warnings:

User deprecated function: Not specifying the signer and key to Builder#getToken() is deprecated. Please move the arguments from Builder#sign() to Builder#getToken(). in Lcobucci\JWT\Builder->getToken() (line 524 of /home/SITE/vendor/lcobucci/jwt/src/Builder.php) #0 /home/SITE/web/core/includes/bootstrap.inc(305): _drupal_error_handler_real()

User deprecated function: Using integers for registered date claims is deprecated, please use DateTimeImmutable objects instead. in Lcobucci\JWT\Builder->convertToDate() (line 169 of /home/SITE/vendor/lcobucci/jwt/src/Builder.php) #0 /home/SITE/web/core/includes/bootstrap.inc(305): _drupal_error_handler_real()

User deprecated function: Replicating claims as headers is deprecated and will removed from v4.0. Please manually set the header if you need it replicated. in Lcobucci\JWT\Builder->setRegisteredClaim() (line 352 of /home/SITE/vendor/lcobucci/jwt/src/Builder.php) #0 /home/SITE/web/core/includes/bootstrap.inc(305): _drupal_error_handler_real()
#1 [internal function]: _drupal_error_handler()

Locally I use PHP 7.4.16 and everything works fine.