Asked is pronounced “askt” not “askd”.
Worked is workt, cooked is cookt, walked is walkt(the “l” here is silent) , kissed is kist, liked is likt, stopped is stopt, looked is lookt, dropped is dropt…
Are you wondering why?
When the last sound before -ed is voiceless (which means you won’t feel your vocal cords vibrate), the -ed sound is /t/.
When the last sound before -ed is
/t/ or /d/ the -ed sound is /id/.
i.e Waited is waitid, wanted is wantid, needed is needid, decided is decidid, hated is hatid, tasted is tastid, ended is endid… (You need to learn how to sound this “id”)
When the last sound before -ed is voiced (which means you will feel your vocal cords vibrate), the-ed sound is /d/.
e.g Played, showed, closed, opened, enjoyed, loved, tried, rained, learned, cleaned.
I hope you found this useful?