1 How to change favicon.ico
2 adding ads is not possible to specify -Custom Attributes-

@Виталий Василенко
You can replace original favicons with your own in folder:
oc-content/themes/veronika/images/favicons

Custom attributes can be set via custom fields feature in osclass.

I wrote down my
/oc-content/themes/veronika/images/favicons/favicon.iso
But there are no changes
http://Http://prntscr.com/ez0clz

Custom attributes added to osclass
But when I add an ad, I can not use them

http://prntscr.com/ez0o0i

http://prntscr.com/ez0nt7

@Виталий
If you look to that folder, there is not 1 icon only (and it is not .iso but .ico).
Remove all files and use your own.
Keep naming convention.

Favicon may not reload immediatelly, check it on google.

With favicon happened. Thank you!

please help with Custom attributes

Custom attributes added to osclass
But when I add an ad, I can not use them

http://prntscr.com/ez0o0i

http://prntscr.com/ez0nt7

I do not know what should I help with.

I created an additional attribute to ads in your osclass
Adminpanel - settings - custom fields

http://prntscr.com/ez21b2

Adding ads is not possible to choose additional options.

For example, if I want to add the parameter "Number of rooms in the house"
how to do it?

http://prntscr.com/ez249a
http://prntscr.com/ez24jy

Where to choose  --- Custom fields ->Condition 

http://prntscr.com/ez250k

Custom attributes and plugin's stuffs can be selected on third step of publishing, when category has been selected.

I chose a category but there is no third stage

http://prntscr.com/ez249a
http://prntscr.com/ez24jy

I do not understand something?
please show where

When I choose category: Спорт и туризм
Fields are loaded correctly.

I recommend to check documentation on custom fields.

Yay it worked ))

at stage 3 there is a mapping plugin -> Custom Attributes

http://prntscr.com/ez2re5

How to make 3 stage was always?
Without Attributes osclass



Again sorry for my English

Found. Can someone come in handy

item-post.php

    // If no category loaded at start, hide hook section
//    if( $('#catId').val() != "" && parseInt($('#catId').val()) > 0 ) {
      $('fieldset.hooks').show(0);
      $('span.total-steps').text('3');
//    }

@Виталий Василенко
You cannot, as 3rd step is dependand on plugins and category selection.