configuring one-way tls from apigee edge to target server

[justlearning]

am trying to configure a one-way TLS from apigee edge (on-prem) to target server.

have tried the following:

1) created a TLS Keystores and uploaded a self-signed cert (.p12 format)

2) in the proxy target endpoint, set the following:

 <HTTPTargetConnection>
        <Properties/>
        <SSLInfo>
            <Enabled>true</Enabled>
            <ClientAuthEnabled>false</ClientAuthEnabled>
            <KeyStore>ref://my-key-store</KeyStore>
            <KeyAlias>my-key-alias</KeyAlias>
        </SSLInfo>
        <URL>https://myendpoint.com/getData</URL>
</HTTPTargetConnection>

when I try to deploy the project, it says "revision is deployed, but traffic cannot flow."

Also, when I try to do a test connection from the keystores to the target hostname, it says "Invalid Truststore. Unable to find valid certification path to requested target"

any idea what went wrong?