Used public key:
-----BEGIN PUBLIC KEY-----
MEwwDQYJKoZIhvcNAQEBBQADOwAwOAIxAMAyyOArE+BoIgN+pipyf5uki64O8Grs
5Kf6LrBo45Ik7KIlYhn8OJ+kzlz2dhYoDQIDAQAB
-----END PUBLIC KEY-----

You can use the query string to specify the data
Encrypted text: 1234567890123456789012345678901234567
Encrypted raw:
pNvUh*8X kRn.9P$ީZ1'mk:

Encrypted base64 encoded:
cA9OdlVoKjhYIOockfeza8pSbtP0iPe5Lo45UK4kEt6p8qBahLuFMScdbWudszoL
This encryption uses OPENSSL_PKCS1_PADDING and a pre-defined key pair. By an key length of 384, the maximum data length is 37 characters (would be 48 without padding).