The following procedure works only when Internet Explorer contains the trusted root certificate of the issuer of your certificate.
In Internet Explorer, click Tools > Internet Options > Content > Certificates.
Click Import and import your server certificate into the Other People tab.
Click Other People, then double-click your certificate.
Click Certification Path.
If the Certification Path shows that the certificate is OK, you now have the full certificate chain available for export. Click OK, then continue with Step 5.
If the Certification Path is not OK, you cannot use this method. Click OK, then contact your issuer for the certificate chain.
Select the certificate, then click Export > Next.
Select Cryptographic Message Syntax Standard - PKCS #7 Certificates (.P7B) as the format and select Include all certificates in the certification path if possible to include the certificate chain.
Click Next, then specify a filename and path for the file.
Click Next > Finish.
Use this P7B file to import your server certificate into Access Manager.