Do you really wish to do this? Most bids can, no guarantees of course, come in the last few minutes even seconds of the auction, you have 2 + days to run , you could reach a higher price, if not, that high price and bidder will remain as the winner.
If you do wish to end it to that highest bidder now, on the Seller Hub, link below if you're not on it already, go to active listings, tick the little box left of the item and scroll up to the tab Actions. From there select End auction selecting the reason... End to Highest Bidder.
May be best to use a laptop / PC and Chrome to manage the above, the app can be sadly lacking in all options and features on eBay.
Seller Hub found here:
https://www.ebay.co.uk/sh/ovw
@peter4_52
