The datapack adds only a scoreboard and a function tag.
The tag gets called a few seconds after load/reload and you can add to it a function which includes the command: scoreboard players set <PACKNAMESPACE> datapack_list 1. Please also add to your uninstall function the command: scoreboard players reset <PACKNAMESPACE> datapack list.

If your pack requires another pack you can check for it with: /execute if score <REQUIREDPACKNAMESPACE> datapack list matches 1..
and display an error message if it is not installed. Please note that the required pack has to include the function listed above.

Please do these steps to your datapack, so other developers can check if it is installed and it won't make your datapack lag because it are only two commands and they only get executed once!