Обработчик событий сущностей

public interface DynamicCodeContext
{
    /// <summary>
    /// Gets Entity service instance.
    /// </summary>
    /// <typeparam name="TEntity"></typeparam>
    public IContextEntityService<TEntity> GetEntityService<TEntity>();

    /// <summary>
    /// Logs message.
    /// </summary>
    public void Log(string msg);
}

public interface IContextEntityService<TEntity>
    where TEntity : Entity
{
    /// <summary>
    /// Inserts detached entity into context.
    /// </summary>
    /// <param name="detachedEntity">New detached entity.</param>
    /// <param name="checkRights">Determines whether to check the current user's permissions.</param>
    /// <returns>Inserted context entity.</returns>
    Task<TEntity> InsertAsync(TEntity detachedEntity, bool checkRights = true);

    /// <summary>
    /// Updates existing entity in context by detached entity.
    /// </summary>
    /// <param name="detachedEntity">Detached entity.</param>
    /// <param name="checkRights">Determines whether to check the current user's permissions.</param>
    /// <returns>Updated context entity.</returns>
    Task<TEntity> UpdateAsync(TEntity detachedEntity, bool checkRights = true);

    /// <summary>
    /// Deletes context entity.
    /// </summary>
    /// <param name="entityId">Entity Id.</param>
    /// <param name="checkRights">Determines whether to check the current user's permissions.</param>
    /// <returns></returns>
    Task<TEntity> DeleteAsync(Guid entityId, bool checkRights = true);

    /// <summary>
    /// Gets context entity.
    /// </summary>
    /// <param name="entityId">Entity Id.</param>
    /// <param name="checkRights">Determines whether to check the current user's permissions.</param>
    /// <returns>Context entity</returns>
    Task<TEntity> GetAsync(Guid entityId, bool checkRights = true);

    /// <summary>
    /// Get Non Tracking IQueryable to context filtered by condition.
    /// </summary>
    /// <param name="condition">Predicate to filter.</param>
    /// <param name="checkRights">Determines whether to check the current user's permissions.</param>
    /// <returns>Context entity</returns>
    IQueryable<TEntity> Get(
        Expression<Func<TEntity, bool>> condition = null,
        bool checkRights = true
    );
}

    public override async Task AfterUpsert(CustomHooksContext context, Activity contextEntity, Activity detachedEntity) 
    {
        const string url = "https://api.timetta.com/odata";
        const string token = "***";

        using var httClient = new HttpClient();
        httClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token);

        var newActivity = new { Name = "New Activity" };
        var payload = JsonContent.Create(newActivity);
            
        var response = await httClient.PostAsync($"{url}/Activities", payload);
        var responseContent = await response.Content.ReadFromJsonAsync<JsonElement>();

        var idOfCreatedEntity = responseContent.GetProperty("id").GetGuid();
        
    }