@msr19
I don’t understand your confusion. Your questions are not clearly worded, but it seems like you might be asking what you should do if you filed as single in one year (even though you were married) and then received an ITIN for your spouse in a subsequent year.
Your spouse only needs one ITIN. If you filed as single in 2019 even though you were married, but your spouse has now received an ITIN in 2020 or 2021, you should file an amended 2019 return to change your status from single to married, but you do not need to apply for a new ITIN because your spouse already has one. Use the ITIN that has already been issued, and include a brief explanation of the entire situation with your amended tax return. (Amended returns have a space to write an explanation, see if you can fit the explanation in that space without needing to attach an extra page of explanations.)
If you are asking a different question, you will need to be more specific please.
