It appears you need to complete Maryland Form 502SU and insert the amount on Line xx on page 3 and carry the amount to Line 13 of your Maryland Form 502. That means, yes, you may be able to deduct up to a thousand dollars for the donation even if you take the standard deduction.
The charity must have a physical location within Maryland and have filed a Maryland Form 87 in order for the donation to qualify for the up to $1,000 tax deduction.
https://www.marylandtaxes.gov/forms/22_forms/087.pdf
In order to get the deduction, you must attach the necessary documents. The qualified charity should have provided you with the necessary documents.
The deduction is authorized by House Bill 711
https://mgaleg.maryland.gov/2021RS/Chapters_noln/CH_221_hb0711t.pdf
