[Liquid] rsa_encrypt?

[Luverion]

I found references of rsa_encrypt here:

https://knowledgecenter.zuora.com/Zuora_Central_Platform/Workflow/Using_Workflow/Use_Liquid_expressi...

But upon checking the below code, it doesn't seem to be working:

{% assign public_key = '-----BEGIN PUBLIC KEY----- 
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCdlUof3WUjlLwlwva420D5nnXh 
xwOqYAUzHIq/AUzBYkDDla2hTtvspcebiFnKtXWmlZrzu4dNYtvE/2ZPiqrmPl8l 
PZAX74WwDRjMCC8HPGUmt6/2mVtXQ7wM9R1KEe9kX0lLeRLmK+lW24KvSL8U1yat 
WO1TP4GmTZ7Kw21fDQIDAQAB 
-----END PUBLIC KEY-----' %} 
{% assign input = 'encryptedMessage' %} 
{{ input | rsa_encrypt: 'encrypt', public_key }} 

or be present here: Liquid filters (shopify.dev)

I cannot find any reference in the liquid master on this rsa_encrypt expression. Would you be able to share whether it is supported by the latest version of liquid (5.0) and if not, where this reference may be coming from?

Thanks a lot for any help!

Filip