Adding two or more input layers to "Merge vector layers" algorithm in QGIS Model Designer

Question

I try to merge two outputs in a QGIS Model Designer model. How can I add two input layers to the Merge vector layer algorithm? There's only one field for input layers (see screenshot). I tried to add "the other" input as a dependency. Also, I tried to add both inputs there. In none of the versions I tried, the result contained both inputs.

Model designer Screenshot

It only works for me when I export the model to Python and create a list of the input layers.

# Merge vector layers
layerlist = [outputs['CreateSpatialIndex_clip']['OUTPUT']]
layerlist.append(outputs['CreateSpatialIndex_difference']['OUTPUT'])
alg_params = {
 'CRS': QgsCoordinateReferenceSystem('EPSG:2056'),
 'LAYERS': layerlist,
 'OUTPUT': parameters['Av_parzellen_oberwallis_lnnichtln']
}
outputs['MergeVectorLayers'] = processing.run('native:mergevectorlayers', alg_params, context=context, feedback=feedback, is_child_algorithm=True)
results['Av_parzellen_oberwallis_lnnichtln'] = outputs['MergeVectorLayers']['OUTPUT']
return results

Answer 1

I just came across this very relevant question/issue/challenge, that I manage to solve.

The trick is to select the "value" option under "Input Layers".

Value option under Input Layers

Then select the layers you want to input for the merging (on the right, the three dots), it will be named in this case: "Create spatial index_Clip" and "Create spatial index_Difference".

enter image description here