You can apply for a Citibank credit card online, for this, you should:
- choose the credit card from the bank's site, which suits you best
- switch to The Home Depot Credit Centre under its description
- press on the Apply button
- fill in the credit card application form with your details, like contacts, financial information, activity details, etc.
- wait for the decision
- get your credit card
If you have additional questions, you may call 1-888-308-5080.