There can be few ways to solve this problem.
1) Check setting in customizer for this.
2) We can change the color of tags from config/setting_data.json. Find "color_sale_tag", make it transparent.
3) Using CSS code to hide the sale tags directly.
Please provide your website URL. I will check and provide a solution here.
This is an accepted solution.
Please add following code in your assets/theme.scss.liquid file.
Hope this works for you.