Help installing barometer-gauge-card

Hi all
Sorry but Ive been trying to install barometer-gauge-card and have ben able to manually install the repository on HACs, as well as the card itself which I can see on HACs. However I cant see it when trying to add it to my frontend.
I also have it added as a resource and can see it in the www/community/ directory.
The install instructions appear dated as I cannot add it to the ui-lovelace.yaml file which I cant even find.
Can somebody please walk me through a step-by-step for this novice? Date is from a BME280 mysensors module which I have integrated into HA. Have the latest versions of everything. HA is running on a VM linux box…
Many many thanks,
Matt