'An account of life written by oneself' is known as-

'An account of life written by oneself' is known as- Autobiography.

Autobiography (noun)
Bangla Meaning: আত্মজীবনী, আত্মচরিত।
English Meaning: the biography of a person narrated by that person.

Other options:
ক) Epitaph
Bangla Meaning: এপিটাফ; সমাধিলিপি।
English Meaning: an inscription on or at a tomb or a grave in memory of the one buried there.

খ) Glossary
Bangla Meaning: টীকাগ্রন্থ বা শব্দকোষ।
English Meaning: a collection of textual glosses or of specialized terms with their meanings.

ঘ) Index
Bangla Meaning: গ্রন্থশেষে সন্নিবেশিত নাম, বিষয়বস্তু ইত্যাদির, বর্ণানুক্রমিক তালিকা;
English Meaning: a list of items (such as topics or names) treated in a printed work that gives for each item the page number where it may be found.

Source: Merriam-Webster Dictionary, Accessible Dictionary, Cambridge Dictionary.