@33catman66
This has nothing to do with your 2019 tax return (other than a taxable amount).
You want to file the 2018 Form 5329.
See Form 5329 where it states you can file the form by itself.
Regarding Line 55 you can attach an explanation that you took action to take the RMD in 2019.
The notation is RC (reasonable cause), not FC
PS
In my opinion an amended return 1040X is called for.
1040X part III is where the explanation goes.
