The solution for this is to go to settings> system> display> scale and layout> and choose the size that is good for you. This will make everything bigger.
You cannot change the font from your device settings or within the LINE app. However, you can make text bold or change the font size from your device settings.
For PC: · First, open the Line app on your device. open the Line app on your device · Second, click the three dots. click the three dots in Line · Then, select ...