Not really.
Colonialism is proto-fascism or more correctly fascism is merely colonialism turned on white people by their immediate neighbors instead of an empire an ocean away. All the tactics and horrors of fascism were adopted from colonial practices by European empires in Africa, by American settler colonizers in the Americas, etc. The mass propaganda model was designed based on American advertising psychological studies and practices. The only true innovations were mechanization (use of extensive trains, computer systems for organizing the exterminations, etc), and white people being the victims. Fascism itself arose specifically due to the threat of socialism as a way of combating it by the capitalists.
Monarchism is an unjust, vile, backwards, reactionary system of government and rule. It has presided over colonialism but it also predated it and colonialism has also occurred from nations without monarchies (US is prime example, but France is another, they continued colonialism well into the very end of the 20th century long after they chopped off the heads of their own monarchs and some including myself would argue their neo-colonialism has continued right up until recent events like the formation of AES in the African sahel).
Now I haven't thought a lot on this particular question or explored it in depth looking for a connection (maybe you can find one if you want to start drawing lines from x through y to then z) but right now I wouldn't say that there is any kind of direct line from monarchism to fascism per se. Monarchism upholds itself through brutality and injustice yes and is predicated on unjust thinking and supremacy and I suppose one could explore the influence of monarchism and monarchist thinking on the development of colonialism and racism but in truth capitalism and proto-capitalist modes of production are the father of fascism via the development of colonialism.