How do I top up my PayPal USD?

As a cryptocurrency and finance professional, I often encounter questions from users about various financial platforms. One common inquiry I've heard lately is: "How do I top up my PayPal USD?" This query typically comes from individuals who are seeking to add funds to their PayPal accounts in US dollars, perhaps to facilitate online purchases, payments, or transfers. To simulate the tone of a questioner, I would phrase it as: "I'm looking to increase the USD balance in my PayPal account. Can you walk me through the steps on how to top up my PayPal USD? I've heard it's a convenient way to fund online transactions, but I'm not sure where to start. Is it through a bank transfer, a debit card, or another method?