Issue with downloading Newick tree in ete4

[vmikk]

Hello!

When using the interactive tree visualization feature in the latest version of ETE4 (tested with ete4==4.0.0b2), the functionality to download a tree in Newick format via the control panel is not working.

Steps to Reproduce:

• Visualize a tree using t.explore() or via treeprofiler plot. E.g.,:

  from ete4 import PhyloTree
  tre = "(A:3,(B:1,C:6));"
  t = PhyloTree(tre)
  t.explore()
  

• Attempt to download the tree in Newick format using the designated button in the control panel.

The button to save the tree in Newick format does not respond, while other export options like SVG and PDF work correctly.

Additional Information:

• ETE version: 4.0.0b2 (installed with pip from etetoolkit/ete/archive/ete4.zip )
• OS: Linux
• Python version: 3.11.5