Krim: कॄं

Swami Sivananda provided this traditional mantra related to Kali and Krim:

OM Krim Kalikayai Namah

Although there are a few scriptures in English where the mantra appears, none of them explain it. That is for a reason: mantras are to be understood through using them.

Also, be aware that the internet is overflowing with garbage about Hinduism, mantras, Kali, etc. since most people worship the negative aspect of Kali.