If you are using IONOS web hosting and getting the 500 Server Error on pages, then these are steps that you need to follow.

You will be able to find two .htaccess files in the source code at the following locations.

1. .htacess file in root filter
2. public/.htaccess

You need to make the following changes in your both .htaccess files.

Find the following line,

RewriteEngine On

And add the following two lines above that line,

RewriteBase /
Options +FollowSymLinks
RewriteEngine On

Save the file. Do the same in both files.

Clear your browser cache and try again or also try it in incognito window.