Generally speaking, company managers do not need to consult shareholders before issuing debt. It'd be a nightmare because proxy voting has abysmal participation rates. Same thing for issuing equity.
That being said, there is nothing stopping a company from having legally binding bylaws that dictate that debt/equity can only be issued by getting approval from X Y and Z, or only if the stock price is above a certain threshold, or only during the second week of July.
And in turn, shareholders can present proposals to vote on to limit or oust a management that's not doing things how they think it should be done.
Structuring corporations is complex business. So long as you're not explicitly breaking the law or somehow infringing on some stakeholders' rights, you get to write your own rules! There are armies of investment bankers whose job it is to guide them.