Hi and Welcome to the forum, you might want to have a look at the following FAQ which explain where everything is
Welcome to Benefits and Work You don't say which benefit this is in relation to but information about the MR can be found in the relevant guide (in the 'members' section of the site).
You don't need to mention appeal at this stage - you will appeal directly to the Tribunal Service but cannot do this until you have been through MR.
If you have not already requested a copy of the assessor's report, this is worth doing. However, don't delay in getting your MR requested if this has not arrived - DWP do not
have to accept any request that arrives more than 1 month after the date on the decision letter.
You don't need to supply a lot of information to request MR, you can tell DWP that you will send in more information when you have seen a copy of the report and they should allow you more time to get it to them.
May I suggest that you bookmark/favourite this on your web browser now so that you can find it easily in future? This will allow you to return with further questions or comments about your claim without having to start a new topic each time. We ask members to keep everything relating to the same claim in one topic as it helps us enormously - and I hope you will find it useful too