#dropbox #H1B dropbox appointment related question

Hello Everyone,
Anyone able to book H1B dropbox appointment recently? I am looking for appointment in August in any consulate since my dropbox eligibility is ending on August 25th.
What is the good time to check the appointment availability & how many times we can try in a day? I am keep getting the warning message “Reached maximum limit of visiting this page”.
Any suggestions / advise please?