The issue in the provided thread link is different than mine.
I will be attaching photos of the cords & message I receive afterwards in my above post.
the command currently works with just
/fill cords1 cords2 blocktype
Attempting to add either keep, outline, destroy or replace makes it give an error message on ps4 1.19.81 (just got update)
the commands I use are:
/fill cords1 cords2 blocktype keep
or
/fill cords1 cords2 blocktype [keep
its the same format for the other block states each time I get a syntax error with it identifying the error part being the block state except it has the auto fill option available for it
The update fixed it! Thanks!