Your interpretation doesn't make any sense. Why would the tenant ask the LL to allow the tenant to make payments to pay for tenant's security (monitoring system)? The LL has no relationship with the security monitoring system and is not a part of the contract between the tenant and the SMS.
It makes better sense that the prospect-tenant is asking the LL if it's okay for the tenant to split the SD into payments rather than paying all up front. The correct answer is NO!