Log in to your MathWorks Account and navigate to the downloads section. If R2019b is not immediately visible, look for a "select version" or "previous releases" link.
MathWorks, Inc. MATLAB. version 9.7 (R2019b), Natick, Massachusetts: The MathWorks Inc., 2019. MathWorks MATLAB R2019b Free Download
For quick use without a full installation, MATLAB Online offers a basic free version (up to 20 hours/month) that requires no download. 2. Preparing a Paper with MATLAB Log in to your MathWorks Account and navigate