What Firewall is this? if you like to reach
From 10.20.20.X to 10.20.98.X
From 0.20.98.X to 10.20.20.X
Do you FW interface part of this network ?
if not you need routing towards FW Layer 3 interface , from FW you need to route back to their respected Gateways.,
you need also ACL to allow bi-directional allow list both subnet can talk to each other.
high level looks like below ( please clarify)
10.20.20.X ----- FW------ 10.20.98.X