Your software
My Mautic version is:4.4.9
My PHP version is:8.0.29
My Database type and version is:

Your problem
My problem is:
Warning : require(/var/www/html/vendor/autoload.php): failed to open stream: No such file or directory in /var/www/html/autoload.php on line 3

These errors are showing in the log:

Steps I have tried to fix the problem: No

Assuming dependencies are installed:

generate autoload class:

composer dump-autoload

if they are not installed, download them from github release page.

Thank you.