You are right that it is better to teach how to do the searches, I have put links to that page before, surely this is not the case, but I have encountered cases that did not know how to use it, especially if there was no direct equivalent and they had to retouch the values for the search.
Greetings.
The main problem is to find one that Djzard20 has on hand, I suppose you will have to make a list with all the equivalents and then look for them in the workshop, I would start with the list on the alltransistors page, in the replacement search a table with Some of the features already set, Lugo looking at the datasheet would add or modify the missing ones, finally take out the equivalents by first modifying the Caps (encapsulated) for example sot323 sot23 sot89 sot223 to92 and then slightly increasing the voltage values.
None of the replacements are sold at my location. so I decided to do a search of different npn transistors to try to find one with specifications similar to those of 2sc4081 and I found only 1. (PMSS3904) I feel tempted to replace it with it. but I don't know if the result of the test is that the PMSS3904 burns or causes other damage to the circuit
Look at the comment of MANOLOACK, the partner truly understands more than me in alternatives, modify the list of the link with the changes proposed by the partner.
Surely something you find
I don't want to make more mistakes so I'll be honest I wouldn't know how to modify it
If in doubt, write and at least help you asking for assistance
A hug and thanks to MANOLOACK