Can we connect more than one loadcell to one HX711 aplifier without summing or junction box? If yes how should the connection be and is there any example reading software?
2 would probably work OK together but you might run into trouble with more 3 or 4. Without a summing box, the won’t be as accurate as with a single load cell and you’d be connecting these in parallel. No changes to the code but you will have to re-calibrate after adding more load cells.
I’m not an expert with multiple load cells so if anyone else has more to add, please jump in. 
Yes, the wires from the load cell should be electrically parallel. Connect each like function to the others. For a given brand and model load cell, this will probably mean to connect all of the red wires to each other, and all of the greens, etc. A junction box makes this easier to install as well as troubleshoot in case of later problems.
Two load cell systems are not too common of a configuration (difficult to balance) but there are many 3-or-more-legged tanks & hoppers. Truck scales frequently have ten or more load cells, though these a better thought of as several adjacent platforms. Here’s a junction box that can be used with ten cells:
[Link](https://www.ricelake.com/en-us/products/product-details/jb1010t-signal-excitation-trim#/information#parts)