Mongoose 2.6 - 4.7 compatible APIS

For our project, we are trying to use SSL APIs in mongoose version 2.6 (which is deprecated) to establish TLS connection. There is some issues in handling SSL sockets and facing TLS SSL_read is failing. WE are planning to upgrade it to 4.7 which is compatible with 2.6, However we are not able to find few APIs that can be compatible with older version. Could anyone please share the docs related on API conversion. We require alternate APIs for version 4.7 for the below APIs used in 2.6. And also What is the TLS version used in 4.7. Is it ok to proceed with 4.7 or can use the latest version.

mg_bind_to_uri
mg_bind_to_error_code