Unable to Change customer Ship to location at Project Task level

Hi I have created project with enabling customer at top task level.

for one customer have multiple ship to ship to address this ship address i have update at task level ship to address for the Perforce of GST Calculation if the Task organization and Ship to location is different it should default IGST. If Ship to location Task Organization is same it should default SGST.

i have changed Task level work site (Location) but Tax rule considering Customer ship to address only How To change ship to address at task level.