'Lease Number' field on the Create Lease Page should generate automatic numbering

We are trying to create Leases in the Fixed Assets Module through 'Manage Leases' » Create a new Lease » On the Lease Creation Page there is a field as 'Lease Number' which we would like to be automatic gapless numbering.

However, in Fixed Assets FSM setups there is no task or configuration where automatic/gapless sequencing can be configured for Lease Numbering. We also checked for any document sequences in the 'Manage Document Sequences' setup, but couldn't find anything there as well to setup sequenci9ng for Lease Numbers in FA module.

If someone has a workaround that helped them enable this for lease creation in FA module then please let us know.