I just copied the text from this website: https://www.androidcentral.com/how-change-terrible-keyboard-your-samsung-galaxy-phone
Hope it works for you
Choosing a new keyboard
If you want to really get into it, there are hundreds of keyboard options on Google Play. You could spend hours and hours researching, but if you want to cut to the chase, we highly recommend starting with one of our favorites.
Google's own Gboard and the ever-present SwiftKey are excellent starting points that millions of people use and enjoy. Critically, they're both leaps and bounds ahead of Samsung's own keyboard. And they're both free!
Install either one of these suggested keyboards, or another you find in the Play Store, and then you'll be ready to switch.
How to switch keyboards on your Samsung Galaxy phone
Install your replacement keyboard of choice.
It will automatically become available in your settings, even if there's no app icon associated with it.
Tap on the Settings app.
Scroll down to General management.
Tap on Language and input.
Tap on On-screen keyboard.
Tap on Default keyboard.
Select the new keyboard you'd like to use by tapping it in the list.
Your new keyboard choice will now be displayed every time a keyboard is needed in the system — the default keyboard will never appear.
Now that you have a new keyboard set as the default, there are a few extra things to know about keyboards on Android.
When you install most third-party keyboards, they will come with additional settings you can use to tweak how the keyboard looks and acts. Sometimes this comes in the form of an "app" in the app drawer that you can tap that takes you to the settings. You can usually access these settings quickly from the keyboard itself — there will often be a settings icon that'll jump right to the same place. If all else fails, head back to the "Language and input" settings for keyboard settings.
You can have multiple keyboards installed at once! Only one can be set as the default, but you can keep several installed if you're still on the fence about which one you like. If you have a need to switch between keyboards regularly, by default, you'll see a small keyboard selection button in the navigation bar any time you have a keyboard open. Just tap it, and you can quickly switch between any keyboard you've previously installed. All of the configurations options stay put.
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