Tenant is forcing me to accept his section 8 voucher

[Maksud H.]

Hello there, 

I need your help. I have a lease with my tenant which is just 3 months old . Currently, the tenant got section 8 approval and asking me to accept the partial amount from section 8 and she stops paying me the amount that section 8 will pay me. So, it seems like I need to sign a contract with section 8 org to get that payment. However, my existing lease with the tenant has another 9 months to get completed. Can my tenant force me to accept section 8 in the middle of an existing lease?