Display Morerabuntu: WP upgrades itself from within the webgui - so it uses the php version which is configured in apache...
Omi Azad: Use phpswitcher an first try php 7.3...
Without phpswitcher it's alot of manuel work... I think there are many posts about this topic in the forum...
/J
I have PHPswitcher. How do I switch between versions if I am not able to install other versions?