Summary and Links:
1. Add your domain in Boost custom domain settings
2. There are 2 ways that you can point your custom domain to Boost:
Cloudflare method: This is the easier way to set up your domain because you won’t have to set up your own SSL certificate. Cloudflare already takes care of the secure connection for you.
See Cloudflare custom domain tutorial here: https://start.boost.link/how-to-set-up-boost-custom-domain-with-cloudflare/CName method: This method requires you to do another step which is to create an SSL certificate. So this method will be likely to take more time than the Cloudflare method.
First, update your CName records to point your domain to Boost: https://start.boost.link/how-to-point-your-domain-to-boost/
Then, create an SSL certificate: https://start.boost.link/how-to-create-free-ssl/
3. Set up custom apps for custom domain
Tutorial for each social network can be found here: https://start.boost.link/how-to-create-social-login-apps/
4. Create opt-in URLs with custom domain and custom app