[Fixed]-How to get values in get_context_data

First you have to guarantee that your context['object_list'] has your objects, so please check that.

If you want to concatenate your url, count and start you could use the values_list function with the flat argument and join them so you have one single string, i.e.:

final = '-'.join(context['object_list'].values_list('url', 'count', 'start', flat=True))

This would result in a - separated string, like url_val-count_val-start_val.