The Canada Caregiver Amount, my husband and I both have DTC. Can I claim him on my taxes and he claim me on his? 2022 we didn't claim 30425, can I amend both of ours?

My DTC was approved this year for 2013-2029 and my Husbands is roughly the same. 2023, he claimed me - I didn't claim him. 2022 neither of us claimed eachother. Are we allowed to claim eachother and how far back could I go to amend our taxes?
When they did my re-assessment after approving my DTC they didn't include the Canada Caregiver Amount.