Pass a secret key to Server Action using a data attribute or a hidden HTML element (See reco)?

Whats up guys?
I need to pass a unique client secret key from SC to Stripe.js on the client side.
How do I use a data attribute or a hidden HTML element (your recommended method)?
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…or does your Stripe Element take care of that in the background when it calls the API action?

Making progress with our complexe Stripe Connect setup (which includes off session charges and application fee). Will share tuto when done.
Thanks!