Hi,

Update the line like this,

    'context': {'default_dst_path': dst_path}

Thanks

this may help you to understand  more how to pass values using context in wizard
     Explanation from  '" odoo development Cookbook "'

Using the context to compute default values
There is a feature of the web client we can use to save some typing. When an action is
executed, the context is updated with some values that can be used by wizards:

active_model  : This is the name of the model related to the action. This is generally the
model being displayed on screen   

active_id : This indicates that a single record is active, and provides the ID of that
record

active_ids : If several records were selected, this will be a list with the IDs (this
happens when several items are selected in a tree view when the action
is triggered. In a form view, you get [active_id])

active_domain : An additional domain on which the wizard will operate

These values can be used to compute default values of the model, or even directly in the
method called by the button

That was too easy, thank you :)