how to convert a Integer to Text value in Power BI

Try

= "Text" & Number.ToText(Number)

You must use the function format. The first argument is the value itself, and the second one is the format you want. Use "string", like the code below:

=FORMAT([RegionID], "string") & " " & [RegionName]

Make sure you have the correct format string.

Try this:

= FORMAT(table1.[RegionID], "#") & " " & table1.[RegionName]