Just got a detailed reply from PCT via email. Quite honestly, I didn't expect such a detailed mail from PCT.
I hope someone will find this info useful.
In order to submit an online request to the IB to publish an international application before the expiration of 18 months from the priority date, select the Action ‘Request for early publication.’
Open the application in your Workbench after signing in to ePCT with strong authentication methods. Go to the ACTIONS section and click the small triangle to open the section and select the action.
The system will warn you if technical preparations for international publication are too close to completion, or indeed are already complete, and it is therefore no longer possible to request earlier publication.
Note that, if the IB has not yet received the ISR or the Declaration under Article 17.2(a), information is displayed as to the payment of the special publication fee of 200 Swiss francs. Note that it is not yet possible to pay this special publication fee online in ePCT and a separate invoice will be issued by the IB.
Before submitting it is compulsory to sign the Action by selecting a signature option. You can either submit immediately or save a draft of the Action to be submitted later. After submitting, the rendered documents are displayed in the Documents section making up the Record as held by the IB.
In general, in case of a request for early publication, the application is published between, 6 and 10 weeks after the request and payment made