Hello,
If you want to turn off the Sale Label in percentage, you can go to Dashboard > Theme Settings > Shop > Product Labels > there you can turn off the toggle button for this: https://ibb.co/qstLN8n
If you completely want to hide the Sale Label without the percentage too then please try using the below Custom CSS code and paste it to Dashboard >> Theme Settings >> Custom CSS >> Global CSS section:
.product-labels .onsale.product-label {
display: none !important;
}
Note: If you just want to show the Sale Label with Sale text only then you don’t need to apply the CSS just turn off the toggle button only.
Hope this helps !
Best Regards