Question about “確定申告控の写し”

I’m applying to sponsor my younger brothers visa to come visit Japan for around 2 weeks (need visa to come to Japan) and I’m stumped about the 確定申告. I’ve working at my company in Tokyo since 2022 as a full time employee and I’ve never had to do anything for my taxes ? It has all been done by my company for me and from what I can see by researching, seems like most people do the 申告 by themselves.

Now i need the above document to sponsor my brother, but I genuinely don’t where to get it. It says I can get a copy of it from the tax agency office where I would’ve submitted it, but I’ve never even submitted one so I don’t even know where I should go. And then theres also the bit where it says people who earn less than a certain amount of money don’t even need to do it in the first place.

Is there anyone who knows what I can do to get my hands on this piece of paper?
[https://www.mofa.go.jp/mofaj/files/000472950.pdf](https://www.mofa.go.jp/mofaj/files/000472950.pdf)
this is the link where it mentions I need to submit in order to sponsor the relatives visa.