To type directly with the computer keyboard:

• Type aa to get ā
• To add a diacritical mark, type an apostrophe; example: t', j' (or c), H' (or x), d', s', S', T', G', k' (or g)
• Type tt, dd, rr for the Urdu special characters
• Type h' for ʰ
• Type - to add the hamza: a-, u-, h-, y-, e-
• Type y-- for ئ
• Type &a, &u, &i to add the diacritics and && for the long consonant
• Type a dot twice .. for the full stop

Download & install the font Noto Nastaliq Urdu