Sqlite is simple file based database; you just need to add reference of below packages in your API project and need to configure path to DB file.
Microsoft.EntityFrameworkCore
Microsoft.EntityFrameworkCore.Design
Microsoft.EntityFrameworkCore.Sqlite
Microsoft.EntityFrameworkCore.Tools
Once you will create DBContext, you need to create migration and need to update database, below are CLI commands for the same.
1. dotnet ef migrations add Name_Of_Migration
2. dotnet ef database update
Note: No need to create sqlite db file separately once we will update database with migration it will automatically create DB file.