If you are in the UK you could either check out the Kennel Club Assured Breeder Scheme, or contact a breed club for advice. The parent club is The Basset Hound Club UK, on that page you should find links to the regional clubs too. I have to say that you may have a long wait - many responsible breeders curtailed their breeding plans during lockdown, - just as the demand for puppies rocketed! Be patient, things will eventually settle down to normal levels - don't be tempted into paying the ridiculous prices that the rip-off merchants are asking on selling sites.