Updating the forge version of someone else's modpack

[KuhakuORIGIN]

Hello everyone,

I have come here today to ask on how to update/change the forge version of a modpack made by someone else.
I tried just using the latest forge.jar file to update it by going to .technic in the files, but it is unable to find a launcher profile.
I am talking about the modpack Optifine Forge 1.16.5, which is just a modpack with only optifine and a 1.16.5 forge, but forge released a newer version for 1.16.5.
How would I go about updating this modpack?

Didn't mean to post this twice, and I have no idea on how to delete a topic, apologies!

Please post your answers in this post and not the OLDER version.

I apologize for accidentally posting this twice.