What form is used to allow the landlord to remove my mother's belongings since she is in hospice and I am living 3,000 Miles away?

I am the only child and I have no POA. My Mother is in hospice and she will not be returning to her apartment. The landlord has agree to remove Mothers belongings since her rent is up at the end of the month, and she will donate or dispose of these items since I cannot do so myself due to living 3000 miles away. Which form do I use to give her the authority to do so? I think it’s called some type of abandonment form? Anyone?