Hi, I am trying to complete the trail editor certification but I am block on the developer edition. I cannot validate the next steps in my trailhead training and I cannot change the URL I use under the developer edition Org

Hello @Nathalie Dongmo make sure the instance you verify is the one in which you have done the configuration. If you keep facing technical issues like this one, please create a brand new dev edition/playground (depending on the module) and try again to configure it & verify the challenge. Eric