I’m sorry that’s a bug. But you can download the config, edit the changes in the editor of your choice, and then run the telegraf config by providing the path to your telegraf file.
Can you please submit an issue for the bug though?
@Anaisdg Tanks for your reply.
I created an Issue: telegraf config could not be changed -> missing button · Issue #1667 · influxdata/ui · GitHub
Unfortunately, I can’t find the option you describe. Could you please add some details?