This bug is a copy of https://bugzilla.redhat.com/show_bug.cgi?id=2137616 as fix needs to go on OCP side.
For must gather and attached screenshots please refer the bugzilla.
Add Capacity button does not exist after upgrade OCP version [OCP4.11->OCP4.12]

Note:
Originally issue is with OCP 4.12 and ODF 4.11, but we need to merge fix in OCP 4.13 (current master branch) then backport fix to OCP 4.12 that is why we need this BZ to merge PR in master branch then after that BZ: https://issues.redhat.com/browse/OCPBUGS-2874 will be used for merging the fix in release 4.12 branch.

Original versions on which it was tested:
ODF Version:4.11.3-3 
OCP Version: 4.12.0-0.nightly-2022-10-24-103753 
Provider: AWS

Since this BZ's target release in OCP 4.13 we need to test on OCP 4.13 and ODF 4.12

1.Install ODF4.12 +OCP4.12
2.Upgrade OCP4.12 to OCP4.13
3.Log in to the OpenShift Web Console.
4.Click Operators → Installed Operators.
5.Click OpenShift Data Foundation Operator.
6.Click the Storage Systems tab.
7.Click the Action Menu (⋮) on the far right of the storage system name to extend the options menu.
"Add Capacity" button does not exist on menu.
*Attached Screenshot