Once You have accepted a job offer from a company.(Make sure you have made all the research before accepting the offer.) It is your duty to inform the current company about your new beginning.
It would not be a good idea to abscond as it doesn’t just weakens your career line , but also creates a bad impression on the employer. The ideal way to inform the current employer is have a meeting and post discussion draft a official resignation email to the current employer.
We have made a few list of thins to avoid saying when you are quitting your job.