Progressive overload means asking a little more from your muscles over time. It's how your body changes.
It doesn't only mean lifting heavier. You can progress by doing more reps, keeping better control, or moving up in weight. Small improvements add up. You don't need a big jump every workout.
Home workouts (follow along)
At home you train to the timer. The timer is your rep range. Your job is to pick a pace and a dumbbell heavy enough that the workout feels tough.
The rule: the last 2 or 3 reps before the timer ends should feel hard with clean form. If the timer runs out and you could easily keep going, go heavier next time. If your form breaks, go lighter.
Gym style workouts
In the gym you count reps, so use ranges:
Compound lifts (squats, presses, rows, deadlifts): 8 to 12 reps.
Isolation exercises (curls, extensions, raises): 12 to 15 reps.
Always go heavy. To build muscle and strength you want to reach failure or stop 1 or 2 reps short of it on your working sets. When you hit the top of the range with good form, add weight next time.
How to know it's working
Feeling easier means it's working, now make it hard again. Same workouts, heavier dumbbells, that's the whole progression system. Your body only changes when it's asked to do something it finds difficult.
Heavier, not longer.