Assign Cost Center to GL Acct. in MIRO

Hi Experts,

I am facing the issue while MIRO

"Field Cost Ctr is required field for G/L XXXXXX".

Can we assign Cost Center Manually to GL in MIRO?

Since I made changes in OKB9 (assigned Cost Element and entered Plant to it, assigned Cost Centers to plant) as well but it is not showing any Cost Center in MIRO after OKB9 activity.

Please guide.

Thanks & Regards