Thanks. Zwift support have said the Tickr X is not officially supported in terms of pace data and may have significant accuracy issues.
I think the basic choice for under £90-100, without being able to purchase a Zwift Run Pod currently, is to go for a Polar Stride sensor for around £50.
I’d also need a Bluetooth dongle for a few pounds too, as my desktop inexplicably doesn’t have built in BT and I’ve never been consistently successful with a Companion App bridge.
Thanks to all!