Ports: non-Github/Gitlab submodules

Hi everyone this is my first question here on the mailing list, sorry if
that question has been asked before. Im currently trying to create a port for a piece of software which does seem to have some submodules as dependencies (C-lang), which have to be initialized before compiling.
In the porters handbook (5.4.3.1) I found out that it can be done for GitHub/GitLab using GH_TUPLE, but one of my dependencies comes from a forgejo instance, so I figured out how to do
it using MASTER_SITES and DIST_FILES to get that file downloaded and extracted but figure out how to specify where it should be extracted.
How can I achieve that? :)

luxanna
Hän/hän or It/its