How to select PHP version for upgrade from RHEL7 to 8

We're trying to perform an upgrade from RHEL7 to 8, using LEAPP, including upgrading our own packages.
By setting up the appropriate repository for our packages, these are taken into account for upgrading. However, some depend on PHP version 7.4, while the standard upgrade with leapp selects PHP 7.2.

How can we enable the php:7.4 module during the upgrade and select the php 7.4 packages instead of 7.2?