How to avoid Oracle Sequence gap?

Hi All

Kindly, I need to create a sequence with no gap of 100%, what is the optimal way to achieve this?

as shown in this demo video, I created a Sequence with no cache and still, there is a chance to get a gap if there is any transaction did not commit due to any reason, is there is any way to avoid this?

https://youtu.be/ynlUtIGSP2Y

this is the steps I follow to produce the issue:

-- Create table

create table rep.t1(s1 number,a1 varchar2(100));

-- Create sequence

create sequence REP.seq1

minvalue 1

maxvalue 999999999

start with 1