ORA-06512: at "SYS.UTL_HTTP", line 1577 ORA-28750: unknown error

getting below while trying to get details after importing certificates.

ERROR at line 1:

ORA-29273: HTTP request failed

ORA-06512: at "SYS.UTL_HTTP", line 1577

ORA-28750: unknown error

ORA-06512: at line 1