When your campaign ends and you no longer want to receive donations through the site, but would still like to keep it online, you're able to turn off donations for your campaign.
Step 1: Login and navigate to your Settings.
Step 2: Select Donation form in the menu on the right.
Step 3: Switch the "Enable Donations" toggle from on to off.
Step 4: Save. Now, there will no longer be a donation button available on your site, and the direct link to the donation form is also no longer enabled.