After you install the add-on, go to add-ons section of your endpoint and copy the url on the right side of the line that says "Metis - Jupiter V6 Swap API". Then simply make any valid REST request to that URL as documented here:
https://quicknode.notion.site/Metis-Jupiter-V6-Swap-API-7c80c4bff22b4f05a58c86ba84f6da45
For the official Jupiter Docs for /swap, see here: https://station.jup.ag/docs/apis/swap-api
For the official Jupiter Docs for /price, see here: https://station.jup.ag/docs/apis/price-api
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