Besides what Solution 1 suggestions, which won't work in a cross-platform framework. There is an SDK by Microsoft, which you can use in .NET Core, since .NET framework and .NET Core (or .NET Standard) have a different mode of dependencies, and platform support, so they require a bit of "brainstorming" before choosing which to use and where.
Besides, you might also be interested in the following posts,
Creating a Word Document OutputFormatter in ASP.NET Core
Read/Write Word Document in Asp.Net Core | The ASP.NET Forums
One thing to note is, that you need to be very careful about the libraries, when working with these frameworks. They are two different things and support different layout of dependencies, NuGet support and runtimes. Things do look similar, but only on the outside.
Quote:but In .Net core spire is not compatible.
Same reason, it has to support .NET Standard or .NET Core in order to be usable on .NET Core frameworks.
GitHub - OfficeDev/Open-XML-SDK: Open XML SDK by Microsoft