InvalidPluginException: Unsupported API version in Minecraft Mod

Question

build.gradle

For Compile

repositories {
    mavenCentral()
    maven { url 'https://hub.spigotmc.org/nexus/content/repositories/snapshots/' }
}

dependencies {

    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.8.1'

    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.8.1'

    compileOnly 'org.spigotmc:spigot-api:1.17.1-R0.1-SNAPSHOT'

}

I am trying to develop plugins for myself and later for servers, maybe for selling. When I compile like a jar file it goes okay but when I insert it in a server it will show an "unsupported API" error message. I tried to fix it by removing the API or just setting it to 1.17.1, but then I will get another error.

Console Error

[09:40:36] [Server thread/ERROR]: Could not load 'plugins\mementosproject-1.0.0.jar' in folder 'plugins'
org.bukkit.plugin.InvalidPluginException: Unsupported API version 1.17.1-R0.1-SNAPSHOT
        at org.bukkit.craftbukkit.v1_17_R1.util.CraftMagicNumbers.checkSupported(CraftMagicNumbers.java:304) ~[spigot-1.17.1.jar:3273-Spigot-3892929-376edf4]
        at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:141) ~[spigot-1.17.1.jar:3273-Spigot-3892929-376edf4]
        at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:394) ~[spigot-1.17.1.jar:3273-Spigot-3892929-376edf4]
        at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:301) ~[spigot-1.17.1.jar:3273-Spigot-3892929-376edf4]
        at org.bukkit.craftbukkit.v1_17_R1.CraftServer.loadPlugins(CraftServer.java:409) ~[spigot-1.17.1.jar:3273-Spigot-3892929-376edf4]
        at org.bukkit.craftbukkit.v1_17_R1.CraftServer.reload(CraftServer.java:908) ~[spigot-1.17.1.jar:3273-Spigot-3892929-376edf4]
        at org.bukkit.Bukkit.reload(Bukkit.java:697) ~[spigot-1.17.1.jar:3273-Spigot-3892929-376edf4]
        at org.bukkit.command.defaults.ReloadCommand.execute(ReloadCommand.java:27) ~[spigot-1.17.1.jar:3273-Spigot-3892929-376edf4]
        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:149) ~[spigot-1.17.1.jar:3273-Spigot-3892929-376edf4]      

Plugin.yml File

name: FirstProject

version: 1.0.0 

author: _Mentos 

main:  org.spigotmc.me.mentosproject

api-version: 1.17.1-R0.1-SNAPSHOT

database: false