How to activate webflow for startups 3 months trial for free?

Hello, so I recently subscribed to the webflow for startups plan, and have been looking to activate the account. However, the promo code isn’t working within webflow.
Is there any issue with that?

I haven’t heard of that offer, but the code is likely for a Site Plan rather than a Workspace Plan.
You’d build your site to a functional point first, and then setup the site plan with the code, I’m assuming.

Beyond that, talking to Webflow support is your best option.