How do I know if I have a “HDMI 2.0 or later compatible cable”….. please advise

HDMI cables sold as 5 Gbps “Standard Speed” will support all HDMI 1.2 features.

HDMI cables sold as 10 Gbps “High Speed” will support all HDMI 1.4 features.

HDMI cables sold as 18 Gbps “Premium High Speed” will support all HDMI 2.0 features.

HDMI cables sold as 48 Gbps “Ultra High Speed” will support all HDMI 2.1 features.

HDMI cable overview - HDMI.org

It’s about the maximum bandwidth between devices, so go for 18 Gbps or better, then the cable will never be the issue when one of the devices has an HDMI 2.0 port.

It would be printed on the packaging.

It may be printed on the cable itself (not mandatory).

The following may help: https://www.thetechwire.com/how-to-tell-if-hdmi-cable-is-2-0/