The recommended way to install Jackett on a Synology NAS is through Docker.

If Docker is not supported in your model you can try to install the Mono version, or the package from SynoCommunity.

If you are experiencing this error you need to update the cacert.pem file in your NAS.

This link may be helpful => https://github.com/Jackett/Jackett/issues/7237#issuecomment-592222874