If you're using Nexo or ItemsAdder, you can configure the plugin to automatically copy it's assets into those plugins' resource pack folders. Otherwise, use the "Without plugins" option.
Nexo
Inside Tooltips
Go into config.yml
Set copy-resource-pack to enabled: true
Set the path to path: Nexo/pack/assets
Do /tt reload for Tooltips to generate its assets into Nexo
Do /nexo reload all to reload Nexo
Repeat steps 4 and 5 anytime you update themes or icons.
ItemsAdder
Inside Tooltips
Go into config.yml
Set copy-resource-pack to enabled: true
Set the path to path: ItemsAdder/contents
Do /tt reload for Tooltips to generate its assets into ItemAdder
Do /iazip to reload resource pack
Repeat steps 4 and 5 anytime you update themes or icons.
Without plugins
You will have to first create your own resource pack (if you don't have an existing one already) and then copy the contents of ...plugins/Tooltips/.generated into your resource packs assets folder. After that, host the resource pack somewhere (for example here or here). You will have to re-merge the resource pack after every config change related to themes or icons.
Additional setup
Some conditions require additional plugins. One notable one is PlaceholderAPI. See all of supported plugins here:
Next steps
Check out the Features to get a map of the plugin.