If your pharmacy does not appear in a search, there could be a number of possible causes.
Some small or local pharmacies are not be listed by name as they do not have approval from a nationally-recognized professional organization that works to maintain the health and safety of the US public. Many legitimate pharmacies do not have this accreditation.
Most of these pharmacies still accept RxSpark vouchers. Not appearing in the RxSpark results does not mean a pharmacy is illegal or dangerous. RxSpark only lists licensed US pharmacies.
If you find a better price at a pharmacy that is listed, you can transfer your prescription. Learn more here: https://help.rxspark.com/help-for-patients/can-i-transfer-a-prescription