Most website builders (like GoDaddy, Squarespace, Wix, etc) have some kind of mechanism that looks like a plus sign, or something usually titled 'add section'.

On your website builder, locate the page where you'd like to add the gift card plugin and click that 'Add section' plus sign.

In the menu that pops up, search for 'html'. This will usually produce the option your looking for, which is a short form where you can add some custom HTML. It's often found under a section called 'Files and Web,' so if you're not seeing it, try searching for 'files and web.'

Now, in your Momence dashboard, grab that gift card plugin code by clicking Studio Setup > Plugins > Gift Cards > and copy the code you see.

If the preview you see to the right is not to your liking, you can make changes to this Gift Card Creation page from Studio Setup > Gift Cards > Gift Card Creation Page.