Using open-props in figma-tokens, AKA Tokens Studio for Figma (Figma Tokens).
For example, use this URL:
https://raw.githubusercontent.com/hchiam/figma-tokens-sync-example/main/open-props.figma-tokens.sync.json
Settings > Sync providers > Add new > URL > Name and URL > Save > Tokens.
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However, doing this makes the Open Props tokens read-only, so you can't edit the JSON or add custom tokens right within the open-props list, unless you pasted the JSON content in.
So if you instead manually copy-paste the JSON contents into Tokens > {}
JSON view > Save JSON, then you can also add new tokens in the {}
JSON view or in the Listing view.
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The official OP tokens should work.
Copy this URL into your browser to automatically get the latest version number in the URL:
https://unpkg.com/open-props/open-props.figma-tokens.sync.json