You can search on Baidu.

Left-click the "Ambiguous Japanese Version" to open it. Several music addresses will pop up. Then right-click the address and select "Copy this link".

However, the setting of space background music is a bit finicky. For example, it will not accept music addresses with ellipses. Also, some of the searched music content for this topic may be in Chinese version, so there are many songs with wrong content.

But as long as you search patiently, I believe you will still find it.