In English the term is borderless, prints without a discernable border. An easel is a convenience, not a necessity.
It used to be that enlargers were customarily equipped with a red safe-placement filter. Youd first compose and focus the image to overlap the edges of an upside-down scrap print of the same size paper you want to use.
Then, with the enlarger lamp on, youd place the red safety filter under the lens so that a dim, red image was projected, remove the scrap sheet, and position the enlarging paper on the baseboard in the projected image where wanted and switch off the lamp.
Then youd remove the safety filter and trigger the timer to expose the paper.
The red filter allows placing the paper without exposing it provided that it doesnt stay in the red light for any significant time.
If you dont have the safety filter, you can tape rulers to the baseboard along 2 adjacent edges of the focus/composing sheet and place the enlarging paper against those 2 positioning references under safelight, and then expose.