I have a discount code for Langua Pro but can't find where to enter it at checkout.
We've noticed that sometimes folks find it difficult to see the discount code field. The checkout is designed by our payment processor, Paddle, so we can't change it. But we can tell you how to find the discount code field.
If you're on a laptop: look for 'Add discount' just below the Subtotal and above the tax on the left (if tax applies in your country).
If you're instead on mobile, you have to click 'Show order summary' when the checkout opens and it will reveal the same thing described above for laptops.
Note that certain codes only apply to monthly subscriptions, as annual is already discounted.