Get the score you need for approval
Walmart reports that you're "more likely to be approved" for their Mastercard credit card with a score of 640 or higher. There are user reports of being approved with a score as low as 600. Ensuring your revolving balances are low and that you have less than six inquiries will help.
Your best odds for approval come with a credit score of 640+. What if your score is too low? Dispute any incorrect items on your credit report with a reputable company (like Credit Glory) for the boost you need!
You can apply for a Walmart credit card in person at the store, or online. In either case you need your SSN and other identity verification information.
The Walmart Mastercard requires at least fair credit for approval. You can potentially qualify with a lower score, but the card is only useful towards purchases at Walmart.