As per me Andhra Pradesh Teacher Eligibility Test (APTET) online application process has not start but here I am telling ditaction to fill it for future reference :

Initial steps to be followed before filling Online Application Form

Go to Andhra Pradesh Teacher Eligibility Test (APTET) official website

Click on Application Form

Click on the dialogue box (i.e., WELCOME TO ONLINE APPLICATION)

Confirm the next dialogue box (i.e., Fields marked with ‘*’ are 15compulsory)

Enter your Journal Number issued by
APONLINE or e-Seva / Mee Seva the date of payment of fees and Date of birth.

At the field ‘Attach your latest photograph' Click on Browse button and
attach your photograph and your signature stored on the local machine.

Tick the declaration and enter the verification code.Press Upload

The application will be opened.

Whenthe application form is opened check if the photo is of required size, clear and is of the same candidate of whom the details are to be filled in the application. If the photo is smaller in size, not clear or does not belong to the candidate press 'BACK' button below the photograph on the application form and restart with scanning of the photograph.

Confirm that the photograph is yours and that it is as per the given
specifications.

Fill in the application form as per the instructions given in the User Guide
and Information Bulletin and those offered while filling the Online
Application Form.

After filling all the details press PREVIEW button. This will display the
details submitted by you

If you find all the details correct press SUBMIT other wise press EDIT
and resubmit the information.

On submission of application form online the candidate shall be given reference ID number which should be kept carefully for any kind of
future correspondence.Submission of application can be considered to
have been completed only on receiving reference ID number.

On submission of application form online the candidate
shall be given reference 16 ID number which should be kept carefully for any kind of future correspondence.

Submission of application can be considered to have been completed only on receiving reference ID number

On completion of submission, the candidates shall take a printout of the application and store it for future use. Candidates should not post the printout of the application to APTET office