alternative way to pay for Lightroom mobile app iOS??

I have installed the trial version of Lightroom mobile on my iPad and I want to pay for the annual subscription but I can’t find anywhere that matches on the website website at Adobe I don’t want to pay for it through Apple. is this so hard that it’s the only place to buy it is through Apple? I asked Google AI and it said to go to the Adobe website which I’ve done but I cannot find the mobile app anywhere to pay for it 

then I came across Lightroom Mobile Payment somewhere very hard to find and it was more like $20 almost a month I just want the $11 version that I’ve seen advertised on the App