Thanks Andrea/Zitian
The board is not recognised in Keil Studio Cloud which is the latest mbed online compiler. Responses from the forum suggested updating to beta firmware released in 2022 but this made no difference.
I had better luck with mbed studio where it was recognized and where the ‘Build and Flash’ process appreared to complete successfully. However the example programme didn’t appear to be running as a result as no LED was blinking.
Prior to this I had downloaded a blink programme from the website and copied it across manually and that did work. Note however the download page does state that this related to a depreciated version of mbed.
I will have a look MCUXpresso.
Thanks!