apple watch 4 not picking up ear phones device

I’ve tried all suggested support answers around bluetooth, airplane mode, disconnecting earplugs (ifrogz) from iphone (8) retrying and many other ways, to sync earphones to apple watch (4). Ear phones connect to iphone but not to watch. Turning bluetooth & earphones on, Searching wheel just spins..

So I can’t play a song via watch 4, from library within itunes on apple watch cos earphones wont sync up but i can play a song via watch 4 from iphone with earphones cos earphones are connected to phone via bluetooth.

How can i get bluetooth to find earphones that my iphone uses?! .