Ensure that you reference Microsoft.EntityFrameworkCore to include all the necessary extension methods that would allow you to execute raw SQL commands.
From the source repository I found ExecuteSqlCommand and related extension methods
int count = await context.Database.ExecuteSqlCommandAsync("DELETE FROM [Blogs]");
Found an article that suggested using ADO.Net.
First you grab a connection from the context, create a command and execute that.
using (var connection = context.Database.GetDbConnection()) {
await connection.OpenAsync();
using (var command = connection.CreateCommand()) {
command.CommandText = "DELETE FROM [Blogs]";
var result = await command.ExecuteNonQueryAsync();
}
}