SheerID instantly verifies that you are a member of the military community and confirms that you're eligible for exclusive military discounts online. This allows retailers to make sure they're not offering their military discount to just anyone. It's kind of like a cashier asking to see your military ID before giving you their discount.
On the brand's Semper Save profile, click the "Get Offer" button. You will be routed directly to the page on the brand's website where you can apply for the discount. Enter your personal information (usually name and date of birth) when prompted.
Once your military status is verified and it's confirmed that you're eligible for the brand's discount, either (1) you will receive a single-use discount code to apply at check-out or (2) your military status will be saved to your account with that particular brand and the discount will automatically be applied to all of your future purchases (just don't forget to sign in when you're shopping on their website!).