It's not possible to transfer a domain name to PMP because we are not a domain name provider.
Usually, it's possible to leave your domain name with your current provider and just point it to your PromoteMyPlace website from there. See here for more information on how to keep your existing domain name.
If it is necessary for you to transfer your domain name away from your existing provider, then you can transfer it to another domain name provider such as 123-reg and change the name servers with them to point to your PromoteMyPlace website.
See here for more instructions on how to use your own domain name.