Azure stop supporting PHP7 in early 2023, for any reason you still wants to run PHP7, there is a way. Azure still allows us to run PHP7, this can be done via cli or using Azure Devops to deploy to php7.4 , Php 7.4 is the oldest version they allows.
So, if you want to have PHP7 , PHP 7.4 is your only choice and you need to provision your resource via azure cli or devops pipelines. this can’t be done via Portal web interface.
After you provision it, if you open in web interface, you might see it looks like this.
