For future reference, for LR 7.2 or later: To import old-format .lrtemplate presets, click the "+" button at the top right of the Presets panel and do Import Presets, or right-click the preset group User Presets (or another non-built-in preset group) and do Import.
Note that the menu command File > Import Develop Profiles And Presets won't import old-format .lrtemplate presets. (Just another LR inconsistency.)
None of those answers are working anymore. Nor the hidden files and I tried literally all of them neither the plus button on the presets... this is really frustrating. There's not even a free converter.....
"When I click the plus button on the presets panel and click on the folder with the "lrtemplates" it says "unable to import presents". It works only with xmp files."
Your screenshot adds a crucial detail: you're importing from a .zip. Unfortunately, LR won't import .lrtemplate presets contained in a .zip. You'll have to extract the .zip into a folder, then when importing with Presets panel > + > Import Presets (not File > Import Develop Profiles and Presets), navigate to that folder and select all the .lrtemplate files in it.
When Adobe implemented the new .xmp format for presets, it did a pretty bad job with the user interface, with lots of rough edges that continually confuse many, many people: