Should be on your invoice. Saying "This serves as a release of liability for.........................business name, in the event of a slip, trip, or fall during or after the completion of service. No 100% guaranteed removal of any traffic lanes, spots, or stains etc. Added lock out fees etc should also be indicated on the invoice in case you are unable to gain entry at the scheduled location.
With every job we require a signature of homeowner/renter agreeing with your terms. With in those terms we have a slip and fall wavier to cover are business. You can add those terms to the housecall pro app under setting- terms.