Sure, if you’re in my boat, you know the only one, true, authentic, and de jure way to obtain Windows 98 is on a physical CD, either as unsold stock or on the used goods market. But, if your target is virtualization, what if you want to eschew with the redundant physical round-tripping? Well, then suffice it to say, you can go searching around on the Internet, and what you will find for sourcing will keep changing from one year to the next. This is what I found from a search this year.
Noteworthy is that only the OEM Windows 98 discs will boot, according to this site.
20190404/DuckDuckGo windows 98 se
20190404/https://winworldpc.com/product/windows-98/98-second-edition
20190404/https://forum.winworldpc.com/discussion/6677/redirect/p1
20190404/https://winworldpc.com/about