Per NIST SP 800-90B – Section 3 – Entropy Source Validation : This Recommendation provides requirements for validating an entropy source at a stated entropy rate. Validation consists of testing by an NVLAP-accredited laboratory against the requirements of SP 800-90B, followed by a review of the results by CAVP and CMVP. Validation provides additional assurance that adequate entropy is provided by the source and may be necessary to satisfy some legal restrictions, policies, and/or directives of various organizations.
I was looking for NIST/FIPS approved list of entropy sources ? something similar to the algorithm list : https://csrc.nist.gov/Projects/cryptographic-module-validation-program/validated-modules/Search