Man pages matching name evp_pkey_set1_rsa in section 3ssl:

EVP_PKEY_set1_RSA.3ssl.en	debian 10 / libssl-doc
EVP_PKEY_set1_RSA.3ssl.en	debian 11 / libssl-doc
EVP_PKEY_set1_RSA.3ssl.en	debian 12 / libssl-doc