This may be a plugin or theme conflict. Please attempt to disable all plugins, and switch to the default Twenty Twenty theme. If the problem goes away, enable them one by one to identify the source of the problem.
If you can install plugins, install Health Check. On the troubleshooting tab, you can click the button to disable all plugins and change the theme for you, while you’re still logged in, without affecting normal visitors to your site.
This is definitely a theme/plugin issue. We can access the /license.txt file, which means we are hitting the server and we are resolving to the WSOD which is related to plugins/theme or sometimes a bad .htaccess file. You can also disable your plugins by renaming the plugins directory in the /wp-content folder. To switch your theme you will need to access your database. If you are not familiar with PHPmyadmin and how to make changes safely then you will need the help from someone who knows how to do that.
I can’t access to wp-admin. I already tried by disabling all the plugins and by switching themes through the database.
