What’s the best ways to becoming an authorized user? I’m 23 with multiple cards but my credit age averages out to 1 year and I want to boost that becoming an authorized user before going for business credit

I got this in the mail today and have until March 25th to redeem it and I already wanted this card or the business plus to be my first business card but I’m still waiting for my first 2 Amex personal cards to come in the mail though so I’ll won’t just jump into this one just yet I’ll definitely get this before it expires though for sure

I just refinanced my car today at DCU and I heard they only pull Equifax and that you can triple dip and I think it’s true but I only double dipped with the auto loan and personal credit card with a $5k limit but they did ask if I wanted a personal loan when I asked if there’s anything else they ofter but I declined I got what I wanted. I might go back for the business side because i currently have zero business accounts besides business checking

So I applied to refinance with DCU Saturday and got approved but I need to become a member to get the auto loan so I’m about to go in today, moral of the story is I heard DCU gives up to 3 approvals with one inquiry so I’m going to find out if that’s true or not and go for a business card or maybe just a personal or both. (They only pull Equifax and aren’t inquiry sensitive, I applied with 5 inquiries on my report)

Happy New Year!! Does anyone have a preferred HYSA they recommend?