It must be issued now, and the bond market interest rate (that is, the real interest rate you said) is the rate of return that bonds with the same risk level are worth investing, that is, what is the public's rate of return on investment? There are many ways to determine the real interest rate, such as referring to bonds with the same risk level and calculating their market interest rate as our real interest rate. You can also get the desired real interest rate through risk adjustment, that is, add a certain risk rate of return to the yield of short-term treasury bonds (treasury bonds are issued by the state, and the state has tax as a guarantee, so there is almost no default, but enterprises are different, and the operation of enterprises has a lot of interest. Therefore, there is a big question mark about whether the debt and interest can be repaid at maturity, which means there is risk, so you have to compensate for the risk, that is, add the yield higher than the national debt as the risk yield to the risk-free yield.