Hash Variables not resolving in Post Form Submission Processing JSON tool URL

I am doing a JSON tool in Post Form Submission Processing as follows:

#envVariable.appServer#/jw/web/json/monitoring/running/activity/complete?processDefId=#form.invoiceinfo.processDefId#&processId=#form.invoiceinfo.paymentProcessId#&activityId=#process.activityInst.notifyProviderToCompleteForm.instanceId[{form.invoiceinfo.paymentProcessId}][{form.invoiceinfo.paymentProcessId}]#

When this JSON tool executes the System Log shows that none of the Hash Variables have resolved.

INFO 03 Jan 2023 17:43:06 org.joget.apps.app.lib.JsonTool - POST : http://ws1.ifcsn.org:8080/jw/web/json/monitoring/running/activity/complete?activityId=%23process.activityInst.notifyProviderToCompleteForm.instanceId%5B%7Bform.invoiceinfo.paymentProcessId%7D%5D%5B%7Bform.invoiceinfo.paymentProcessId%7D%5D%23&processId=%23form.invoiceinfo.paymentProcessId%23&processDefId=%23form.invoiceinfo.processDefId%23
2845
INFO 03 Jan 2023 17:43:06 org.joget.apps.app.lib.JsonTool - Adding request header Authorization : Basic (Removed here)
INFO 03 Jan 2023 17:43:06 org.joget.apps.app.lib.JsonTool - Adding request header Authorization : Basic (Removed here)
INFO 03 Jan 2023 17:43:06 org.joget.apps.app.web.JsonResponseFilter - Possible CSRF attack from url(/jw/web/json/monitoring/running/activity/complete) referer(null) IP(35.157.187.193)
2848
INFO 03 Jan 2023 17:43:06 org.joget.apps.app.lib.JsonTool - http://ws1.ifcsn.org:8080/jw/web/json/monitoring/running/activity/complete?activityId=%23process.activityInst.notifyProviderToCompleteForm.instanceId%5B%7Bform.invoiceinfo.paymentProcessId%7D%5D%5B%7Bform.invoiceinfo.paymentProcessId%7D%5D%23&processId=%23form.invoiceinfo.paymentProcessId%23&processDefId=%23form.invoiceinfo.processDefId%23 returned with status : 400

Please advise why the Hash Variables did not resolve but were included as literal text.

Thanks in advance, Bill