Step1: Get a list of english words that are 2-6 characters (Google is your friend...
https://eslforums.com/6-letter-words/ )
Step2: Dump this list into a spreadsheet in 1 column, put your keyword in the next. Use the concatenate command to merge them together, and add .com to the end.
Step3: Copy/paste the list into a bulk whois lookup tool (See:
https://www.namecheap.com/domains/bulk-domain-search/ ), keep only available domains. Pick and choose the ones you like best.
Enjoy.
WG