Problem in saving phrases in the app and requesting a recommendation for mobile device that support saving phrases

I can’t mark and save phrases to LingQ in the app on my phone and tablet, and unfortunately, marking phrases is very important to me and it’s difficult for me to learn without it (I mark whole sentences and parts of sentences and that’s how I learn). I thought it might have a problem with the phone or tablet model or version.
My phone: xiaomi redmi note 6, android 8.1
My tablet - Asus Zenped C7 android 5.0.2

Could anyone explain to me how to mark and save phrases (maybe I’m doing something wrong), or alternatively, which android phones or tablets can you recommend that support in saving phrases to LingQ?
Are there any special system requirements for the phone and tablet. maybe an Android versiaon or company or anything else?

Thank you very much :slight_smile: