How to specify an ActionSet in a RewriteRule for azurerm_application_gateway?

I get this error when trying to apply an Azure Application Gateway:

Error: Error Creating/Updating Application Gateway “X” (Resource Group “X”): network.ApplicationGatewaysClient#CreateOrUpdate: Failure sending request: StatusCode=400 – Original Error: Code=“ApplicationGatewayRewriteRuleSetActionSetInRewriteRuleCannotBeEmpty” Message=“ActionSet is a required field in a RewriteRule.” Details=

But in the module documentation there is nothing on ActionSets. I even did a terraform import on a live Application Gateway with Rewrite Rules and it would show any sort of Action or ActionSet block.

This is with both the 1.x and 2.x azurerm provider.

Did you find a solution to this?
I am having the same issue:

network.ApplicationGatewaysClient#CreateOrUpdate: Failure sending request: StatusCode=400 – Original
Error: Code=“ApplicationGatewayRewriteRuleSetActionSetInRewriteRuleCannotBeEmpty” Message=“ActionSet is a required field in a RewriteRule.” Details=

Sadly I did not find a solution and could not find a single example of using the Rewrite Rules.