How to export the required certificate from the correct domain
Follow these steps to export the certificate:
Click the lock icon in the address bar.
Select Connection is secure and then click Certificate is valid or the Certificate icon, depending on your browser.
In the Details tab, view the certificate chain and select the topmost certificate (parent certificate).
Click Export to download the certificate.
Choose a directory to save the certificate to your local device.
How to install the exported certificate
Navigate to the folder where you saved the certificate.
Double-click the certificate file to open it.
Click Install Certificate in the certificate details wizard.
Choose Local Machine as the store location and click Next.
Complete the wizard and click Finish.
Once the installation is successful, a message will appear:
“The import was successful.” Click OK.
Note : To prevent future validation issues, ensure the remote device has automatic root certificate updates enabled. How to enable automatic root certificate updates
To enable the automatic root certificate update on a Windows machine via the Group Policy Editor:
Press Win + R, type gpedit.msc, and press Enter.
Navigate to:
Computer Configuration > Administrative Templates > System > Internet Communication Management > Internet Communication settings
Double-click Turn off Automatic Root Certificates Update.
Set it to Disabled to enable automatic updates.