Keyword set 1
Select your preferred top level domain, e.g. .com.
Choose how many keywords your domain should be made of, e.g. TheAwesomeBlenders means 3 keyword sets.
If you go with 3 sets.. then put a first word in the first keyword set, e.g. the, a second word awesome to the second keyword set and a third word blenders to the third set.
Hit the generate domains button above.. you will get availability for the theawesomeblenders.com domain.
If you want to check availability for thebestblenders.com as well, then put the word best alongside awesome to the second keyword set.
NOW.. if you want to check availability for bestblenders.com and awesomeblenders.com without the first keyword set containing the word the >> restrict the keyword sets from 1 until 3 to 2 until 3 with the usage of slider above.
What about blenders on .io top level domain.. choose the last option for TLD and provide your desired domain extension.
ONE LAST THING.. sometimes you need to use synonyms because domain is already taken.. CLICK on the word in the keyword set, e.g awesome, and see some synonyms from a dictionary.
You might want to check the buttons under each keyword set text input.. it might do your domain research easier.
If you want to just check several fully qualified domains for availability, consider using much simpler tool