Then you “accidentally” forget your cell phone in the car or at home. You don’t need it when you’re writing.
Turn off the Internet.
Or even better: buy a cheap notebook for 200 euros and have a specialist remove the WiFi module. Then you'll practically have a 21st century typewriter.
My phone is always in airplane mode. My internet is azerbaijan telegram screening disabled (so I don't do research and accidentally end up reading interesting historical facts that I don't need).
Focus is the key to success. And you can only get that in a bunker. Isolate yourself. At least for an hour.
If you can't work undisturbed at home or in the office, go to the local library. It doesn't matter where you write - the main thing is that you won't be disturbed.
In his book “The One Thing,” Gary Keller explains in great detail how important it is to work on just one thing.
There is no such thing as multitasking – there is only multiswitching.
This means that your brain is constantly jumping back and forth between different activities. This back and forth consumes a huge amount of brain capacity and makes your content production process as sluggish as old chewing gum.