Hello, I’m trying to send a custom value from my WordPress page into Botpress Webchat v3.5, so that the Main workflow can receive it and include it inside the JSON body of an Http Request within the flow. I tried doing it with custom events, but it doesn't share the received data with the main workflow.

Hi, use webchat's updateUser() on your page and the GetUserData card in Botpress. https://botpress.com/docs/webchat/interact/send-user-data