You can use a tool to convert it to the latest bedrock edition then change the bedrock version back to the latest Java version, that’s what I did with one of my packs. Or if you can find it, you can use a tool that just updates the pack layout without changing it to bedrock first. (If your pack has an “optifine” directory inside the pack, option 1 of what I said will not work, you would have to use option 2)
if you could reply me with a link for the download of the pack I can do it for you.
