How do I restrict my uploaded files on a system to accept only zip files and word document files?

This is the line of code but I need help on how to go abour=t the issue above.

                <div class="col-lg-12">
                  <div class="form-group">
                    <label for="file" class="control-label text-muted">Project/ Thesis Document</label>
                    <input type="file" id="file" name="zip_file" class="form-control form-control-border" accept="application/zip" <?= !isset($id) ? "required" : "" ?> />
                  </div>
                </div>
              </div>```