If you receive this code it's because:
HMRC holds different details to what has been inputted into Capium prior to the submission attempt
Or
There is a block on your HMRC account.
We advise you check the below:
Your companies House Presenter ID - The Presenter Identifier starts with 000 and ends with 000, is a mixture of numbers and letters and is 11 characters long. This is usually entered in capitals.
You Company authentication code - 6 digit
You Company's Government gateway credentials - Can be up to 12 characters
More information can be found here: https://capium.freshdesk.com/a/solutions/articles/9000236664
If the above login credentials are correct we advise that the best course of action is to contact HMRC.