Convert Duration to Hours and Minutes

Use this in a custom column

= Text.From(Number.IntegerDivide(Duration.TotalHours([Time]),1)) & ":" & Text.PadStart(Text.From(Number.Round(60*Number.Mod(Duration.TotalHours([Time]),1),0)),2,"0")

See the working here - Open a blank query - Home - Advanced Editor - Remove everything from there and paste the below code to test

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMjI10jM0sTK0tDIy0zMxMjYAAqVYnWglEyM9A3MrAyMrIws9S3MDiHgsAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Time = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Time", type duration}}),
    #"Added Custom" = Table.AddColumn(#"Changed Type", "Custom", each Text.From(Number.IntegerDivide(Duration.TotalHours([Time]),1)) & ":" & Text.PadStart(Text.From(Number.Round(60*Number.Mod(Duration.TotalHours([Time]),1),0)),2,"0"))
in
    #"Added Custom"