Can’t remember whether the forum name ends in .com or .co.uk? Your worries are over. You can now reach the forum via a .com, .co.uk, .net or .org address.
Note: For now your browser may complain about an insecure connection on the other domains as there are no certificates installed (so https doesn’t work). This is correct but the address is just being forwarded to the actual site at the .com address, which is secure, meaning the data passed between your browser and the site is encrypted.