How can I move quickly in time? I am a slow chess player. I have 3 digits rating in blitz. How I can play fast so that I do not loose on time ?
I think, yesterday, I have answered such a question here.
I am just pasting the answer and adding a few resources to it. You should keep these in your mind.

Smooth Transition: As per other answers, I think you should try 15+0 [Rapid] &gt;&gt; 10+5 &gt;&gt; 10+0 &gt;&gt; 5+5 / 5+3 [Blitz] &gt;&gt; 5+0 &gt;&gt; 3+2 &gt;&gt; 3+0 &gt;&gt; 2+1[Bullet] &gt;&gt; 1+0, in following manner: If you can complete (win/lose) 10 games in a row within the given time then go for the next tier.

One Opening man: Instead of experimenting with different openings, you must stick with a single one and simultaneously have to study it deeply. After studying a line properly, set a target to play first 10 moves within 10 sec. If you follow a single line (eg., 1.d4) for more than 100 games; then you will find that it is quite easy for you to reply not only fast but also accurate. And it will help you significantly in time management.

Pre moving: After &quot;mastering&quot; an opening, try to pre-move [This is crucial in the bullet, not in blitz]. Just make sure to play first 10 moves within 5 seconds!! and you will rock on bullet [at least below 1500 tier].

Pattern Recognition in Middlegame: A simple way to play ultrafast middlegame is pattern recognition (eg., if both King and Queen are in the same diagonal, then try to find your bishop to set a &quot;Royal Fork&quot;). The only way to achieve this is by practicing a lot of puzzles. So, be prepared to try at least 20 puzzles (If possible 50) each day.

Accurate Endgames: &quot;All's well that ends well.&quot; So, be focused at your endgame. First, master the checkmate patterns (Staircase mate, smothered mate etc.) and then try the comparatively advance theory (like opposition). If you are already good at endgame, then invite your opponent directly from the opening, by exchanging valuable pieces early in the game.


Here are a few resources you can check:
Beginners training kit at lichess.
Tactics training at Blitz-tactics
Puzzles at lichess
Hope it helps. Good luck.