Thanks for asking question! If I have understood right you want to implement IP restriction.
Access restrictions enable you to define a priority ordered allow/deny list that controls network access to your app.
To add an access restriction rule from Azure Portal to your app, use the menu to open Network>Access Restrictions and click on Configure Access Restrictions.
Please refer to Azure App Service access restrictions for details
For adding an access restriction in case of Azure PowerShell:
Add-AzWebAppAccessRestrictionRule -ResourceGroupName "ResourceGroup" -WebAppName "AppName" -Name "Ip example rule" -Priority 100 -Action Allow -IpAddress 122.133.144.0/24
Let us know if you have questions on this.