mobile app unable to access https Java REST APIS deployed on weblogic

Our mobile team developed mobile app using react native (expo platform), this mobile app is accessing Java REST APIs deployed on Weblogic server,

Client asked to apply client certificates on Weblogic to secure the apis, and we applied the certificates, and when we open the APIs from browser we got a valid certificates and its working fine.

But when the mobile application trying to access the REST apis its failed with: trust anchor for certification path not found

We tried to access the APIs from postman, but we got same issue, but when we attach the certificate on postman its working fine, but the problem is with expo platform you cannot attach the certificate. mobile team tried to attach the certificate but this did not work.

Note: mobile team tried to access another APIs deployed on Sharepoint (IIS). same certificate type is applied there and it accessed successfully without attaching the certificate.

Note: We applied private and public certificate. but its the same with expo mobile platform.

Note: We tried to build app sample using native android and another sample using flutter. and both are working with attaching the certificate on the sample.

We need a solution to access the APIs without attaching the certificate because of expo platform limitation.