Blockquote
<div class="form-floating mb-3">
<input id="file1" name="upload1[]" type="file" class="form-control" multiple="true" accept=".pdf,.jpg,.jpeg,.png,.webp"> <label for="input1" class="form-label">Some text</label><button id="btn1" class="btn" type="submit">Button</button>
</div>
</form>
I was following this thread for the binding.
Set the upload file name to the $_POST and it did not show up in the Error console.
Error console: