Hi @Mohamed Riyaz M,
It is not possible to default the SharePoint Server URL on the SharePoint Mobile App. The user needs to manually enter the URL of the SharePoint Server they want to connect to.
I recommend you give suggestion in the feedback portal and help to make improvements. Many features of current products are designed and upgraded based on customers’ feedback. With requirements like this increase, the problem may well be released in the future. I will vote for you.
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