@Pahari, Anupam Welcome to Microsoft Q&A forum!
To remove the specified area and load the map in full screen, you need to add/specify the height of the map to 100%.
<style>
html, body {
margin: 0;
}
#myMap {
height: 100vh;
width: 100vw;
}
</style>
Please see below screenshots to understand more.
Before:
After:
Hope this helps. Do let us know if you have any further queries.
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