Restore and Write Date Creation from comments previously saved

Hi guys,
I tried to read and try to mixes as many similar topics was talking about date fields but couldn't find anything working as expected, so here I am
Some time ago i made some backup of the Creation Date to the Comment field, now I'm trying to restore it but without success.
for example I can place the date in almost any other field, for example in AlbumArtist and it look like:
16/06/2020 18:25:39
but if I try to paste it (using Actions or Tag-Tag converter) in %_file_create_datetime% it doesn't work..

Actually I have it in this format: 2021-04-17_18:38

I'm pretty sure that the only incorrect step is the format of date that the date has to be, what do you think?

The underscore of the field name indicates that the field is a read-only (information only) field. MP3tag does not write this data.

Here is a (German) thread on more or less the same idea:

there is a link to a file-date-changer.

Thank you @ohrenkino for your fast reply!
I've tried some third software and also the one in the german thread that you attached but couldn't find the thing was looking for.
You reported clearly that Mp3tag doesn't support the writing of Creation/Modified Date fields but I think that is a BIG lack in this great software, and after some time while I was looking around other threads I can say that there were many other that needed this function.

After all, if exist more than one software that can overwrite and change the Creation Date (even some simple command line software) I'm having some difficult to understand that adding this feature would be a technical issue.
Some of that third software gives you even the possibility to use any source file as a date, the only issue is that it would work great only if you want to apply that date in bulk to many files using the same date.. So in Mp3tag it would be even easier as it could use a chosen field as source date.
Hope you got my point of view, and that it could contribute to improve even better this already excellent product!
Thank you

Here is another link on a similar topic:

Thank you for your reply but in that topic the only comment useful I could find was: