Hi Rahul,
There's no automatic way to scale up/down, but you can do it using script. For example, say you wanted to scale down to Basic B1 during off hours, sample code below:
Set-AzAppServicePlan -ResourceGroupName my-resource-group -Name ASP-myappservice-plan -Tier Basic -WorkerSize Small
Right before working hours you could use below command to scale up to Basic B3:
Set-AzAppServicePlan -ResourceGroupName my-resource-group -Name ASP-myappservice-plan -Tier Basic -WorkerSize Large
One thing to keep in mind is before you attempt to scale down to a lower plan you must disable/remove features that are not supported by the lower tier, if you are using them. And then when scaling back up to higher tier reinstate/configure those features. For example, custom domains are not supported by Free tier, so before you can scale down to Free you need to remove binding(s) first.
Please click Accept Answer and upvote if the above was helpful.
Thanks.
-TP