Recording JE for purchase of computer with credit card
There is no JE. You hardly use them, in QB. You want to avoid them for Names. Never for Credit Card entries. Nor for AR, AP, QB inventory, QB Sales, Sale Taxes or QB Payroll.
You have a Program. It has an interface = tools.
Use your Banking menu. Banking menu > Enter Credit Card Charges. This is how you list who you paid and what card it is from, and what you paid for. This increases the running balance in that Credit Card Type of account, in QB.