Error while adding a condition for the sequence flow between forking inclusive gatewat

I am relatively new to Camunda I am trying to learn about inclusive gateways and while I was trying to add a condition ${orderAmount>2000} for the sequence flow between forking inclusive gateway I am getting this error while deploying the process

Cannot instantiate process definition Online_shopping:2:9b55221a-f7f4-11ea-a7bb-5ce0c579446a: Unknown property used in expression: ${orderAmount>2000}. Cause: Cannot resolve identifier ‘orderAmount’ [ start-instance-error ]

Where is your process variable “orderAmount” set?
Uploading the corresponding BPMN would help to solve your problem.